Vanishing Webpage Links Google to Network Maverick Nicira

Proof that Google is using Nicira's network controller? Image: Google

As part of its new-age system for moving traffic between its massive data centers, Google is using a network controller built in tandem with swashbuckling Silicon Valley startup Nicira, according to a Google presentation posted to the web.

On Tuesday, during a speech in Santa Clara, California, Google’s Urs Hölzle — the man who oversees the company’s worldwide network of data centers — revealed that the company is now using an open source protocol known as OpenFlow to completely overhaul the links between the computing facilities that drive its sweeping collection of web services, and a slide presentation that accompanied the speech was posted to the web.

The presentation has now been removed, but an extra slide tacked on to the end of the file indicated that Google is driving its OpenFlow-based network gear using a controller called Onix. Onix serves as the basis for the software offered by Nicira, an outfit that recently emerged from stealth mode touting a new breed of network that exists only as software. According to a 2010 research paper, Onix was designed by four Nicira engineers, three Googlers, an NEC employee, and an academic who was among Nicira’s co-founders. The top four contributors to the paper are Nicira employees.

Google typically treats its infrastructure as a trade secret best kept hidden from competitors. Hölzle’s speech provided a rare window into how a portion of the company’s operation works, and the slide at the end of his presentation is another small glimpse of what is largely regarded as the net’s most advanced operation. Google’s infrastructure is worth watching because it’s typically a bellwether for where data centers are moving, and this is another clear sign the world is moving towards the sort of software-centric networks championed by Nicira and others in Silicon Valley.

Nicira chief technology officer Martin Casado — one of the authors of the Onix paper and the key figure in Nicira’s effort to reinvent networking — declined to comment on Google’s presentation. But he did confirm that Google was “involved” in the creation of Onix. Previously, Casado told us that Nicira’s customers include some of the web’s biggest names, but would not confirm that Google is a customer. The company will say that its customers include AT&T, eBay, Japanese telecom NTT, financial giant Fidelity, and Rackspace, the Texas outfit that competes with Amazon in the cloud computing game.

Asked to comment on the presentation, a Google spokeswoman said: “We’re not a customer of Nicira, but we have worked together with them (and others in the OpenFlow community) on the design and requirements of OpenFlow controllers.”

Nicira is part of a wider effort to move the brains of the network into software, so that it can be more easily managed and modified. Historically, engineers have needed physical access to switches and routers in order to manage their networks. But this new movement — called software-defined networking, or SDN — seeks to reduce hassle and costs by shifting management duties onto servers. Ultimately, says Martin Casado, the man at the heart of this movement, Nicira and others hope to create networks that can be programmed as easily as computers.

Nicira grew out of research that Martin Casado did at Stanford University, working alongside Stanford professor Nick McKeown and University of California, Berkeley professor Scott Shenker. The three of them formed Nicira in 2007, and through their work at the company, they in essence founded the software-defined networking movement.

“Software-defined networking is applying modularity to network control,” says Scott Shenker. “Modularity is something every software designer does in their sleep. If a program isn’t modular, it’s just spaghetti code. Software-defined networking asks what are the right software abstractions that let us structure the network control plane so it’s evolvable, so it’s not just a bunch of spaghetti code.”

Working alongside various other academics, Nicira was the original driving force behind OpenFlow, a standard way of remotely managing network switches and routers. Previously, such a technology was not generally available — though Google has said that it had developed something similar but inferior before OpenFlow arrived and Casado has indicated that other web outfits were doing the same sort of thing.

Google built its own networking hardware to accommodate OpenFlow, and the company first used the technology to upgrade links between its data centers in North Carolina, South Carolina, and Georgia. Then, it began replacing the existing links between its other data centers.

According to Google’s slide presentation, these WAN (wide-area network) links are managed in part using the Onix controller.

Onix is the basis for the network controller Nicira offers to other customers. But in this case, Google is using it a little differently. Google uses the controller to manage physical OpenFlow-based network switches, while Nicira’s controller is used to manage virtual network switches — at least for the time being.

The drawback with OpenFlow is that you can’t use it to manage your physical hardware unless the protocol has been added to that hardware. This is why Google designed its own networking equipment (though some networking vendors are now moving towards OpenFlow). Since OpenFlow was released, Nicira has built a new breed of virtual switch — a switch that exists only in software — and using the Nicira controller, you can create completely virtual networks that run atop any networking gear — whether it supports OpenFlow or not.

But this sort of virtual network is only used inside the data center. It does not apply to the WAN that Google has built between its data centers. It’s unclear how Google is handling its network inside these facilities. Others, however, including Rackspace, are moving to the virtual networks enabled by Nicira. This effort to move networking into software is a threat to established networking hardware vendors such as Cisco and Juniper — it makes it easier to buy low-cost networking hardware from other sources — but the Ciscos and the Junipers are working on their own SDN tools.